Abstract
The non-invasive 133-Xenon intravenous (IV) injection method for measuring regional cerebral blood flow (rCBF) has many advantages compared to the 133-Xenon inhalation method. In order to evaluate the possibility of clinical application of this IV injection method, normal regional and mean hemispheric values of rCBF were determined in this study.
The rCBF data were obtained on 27 normal Japanese right-handed volunteers with an age range of 18 to 81 years (mean age 43).
The subjects were requested to relax, keeping the eyes closed but without falling asleep. End-tidal 133-Xenon curves were used for correction of recirculation. The blood flow of the fast compartment (gray matter) of the brain was calculated, as well as the initial slope index (ISI) and the relative weight and the fractional flow of the fast compartment. CBF values thus obtained were compared to those obtained by the 133-Xenon inhalation method previously reported by us.
The mean gray matter flow values for the right hemisphere was 90.3±17.5 ml/100 g brain/min (mean±S.D.) and that for the left was 90.0±17.8.
The mean value of ISI for the right hemisphere was 75.1±17.0 and that for the left was 74.6±17.0. There was no significant difference of blood flow between the hemispheres. These values were higher than those obtained by the inhalation method. The reason for this difference is discussed.
The rCBF values were the highest frontally and the lowest parietooccipitally in both hemispheres, which is in good agreement with the results obtained by the other non-invasive methods and the intracarotid injection method.
It is concluded that the 133-Xenon intravenous injection method, which has many advantages compared with the inhalation method, is applicable for rCBF measurements in man.
